Brush with improved application and spreading

ABSTRACT

The invention relates to a brush including:  
     a handle ( 400 ),  
     a ferrule ( 300 )/receptacle ( 100 ) assembly joined to the handle ( 400 ),  
     a layer of glue ( 112 ) inside the ferrule/receptacle assembly, and  
     a homogeneous tuft of fibers ( 200 ) which has no built-in spacer, whose first end inside the ferrule ( 300 )/receptacle ( 100 ) assembly is embedded in the layer of glue ( 112 ) and whose free second end emerges from the ferrule ( 300 )/receptacle ( 100 ) assembly, in which brush the tuft of fibers ( 200 ) has an at least substantially homogeneous density throughout its length from its end embedded in the layer of glue ( 112 ) to its free second end, adapted to enable movement of the fibers in the ferrule ( 300 )/receptacle ( 100 ) assembly so that, in use, the portion of the tuft of fibers ( 200 ) inside the ferrule ( 300 )/receptacle ( 100 ) assembly and beyond the layer of glue ( 112 ) can flex, which brush is characterized in that the receptacle ( 100, 400, 500 ) includes arrangements on its lateral walls ( 110, 500 ) which form an anchorage for the glue and said anchorage arrangements ( 115 ) take the form of orifices ( 115 ) passing through the lateral walls ( 110 ) of the receptacle ( 100 ).

[0001] The present invention concerns brushes for applying products such as paint, varnish, glue or other liquids.

[0002] Brushes with a handle, a tuft of fibers and a ferrule, with the ferrule surrounding both the handle and the tuft to join them together, are known in the art.

[0003] It has been proposed to fasten the bristles together at their handle end with a layer of glue. However, the bristles must be fastidiously aligned before gluing them.

[0004] There has also been a requirement to reduce the cost of manufacturing such brushes. To this end placing spacers between bundles of bristles at the base of the tuft to form interstices and thereby reduce the number of fibers and reduce the cost is known in the art.

[0005] However, the interstices form paint reservoirs in the tuft which, although they apply paint for longer each time the brush is dipped into the paint, nevertheless cause a lack of homogeneity in the applied layer of paint and encourage drips from the tuft toward the handle.

[0006] What is more, the fibers disposed in this way constitute a tuft that is flexible only beyond a particular distance from the ferrule. Limited flexibility in the vicinity of the free end of the tuft proves somewhat ineffective in terms of application and spreading.

[0007] We propose a brush that is easy and therefore inexpensive to manufacture but which nevertheless applies paint for a long time on each stroke and homogeneously thanks to a particular flexibility of the tuft of fibers.

[0008] In accordance with the invention, the above object is achieved with a brush including:

[0009] a handle,

[0010] a ferrule/receptacle assembly joined to the handle,

[0011] a layer of glue inside the ferrule/receptacle assembly, and

[0012] a homogeneous tuft of fibers which has no built-in spacer, whose first end inside the ferrule/receptacle assembly is embedded in the layer of glue and whose free second end emerges from the ferrule/receptacle assembly, in which brush the tuft of fibers has an at least substantially homogeneous density throughout its length from its end embedded in the layer of glue to its free second end, adapted to enable movement of the fibers in the ferrule/receptacle assembly so that, in use, the portion of the tuft of fibers inside the ferrule/receptacle assembly and beyond the layer of glue can flex, which brush is characterized in that the receptacle includes arrangements on its lateral walls which form an anchorage for the glue and said anchorage arrangements take the form of orifices passing through the lateral walls of the receptacle.

[0013] With the above features, the tuft has proved to have a high application capacity and a flexibility producing a surprising quality of application, in particular flexibility at the base of the tufts and especially just inside the receptacle.

[0014] By virtue of the above features, a brush of the above kind is easy to manufacture and it is very easy to adapt the nature, length and density of the fibers and their homogeneity, both transversely to the tuft and along their height, in accordance with the products to be applied and obtain a high application capacity and a flexibility leading to a surprisingly high quality of application.

[0015] Other features, objects and advantages of the present invention will become apparent on reading the following detailed description, which is given with reference to the accompanying drawings, in which:

[0016]FIG. 1 is a perspective view of a fiber-carrier according to the invention;

[0017]FIG. 2 is a side view of the same fiber-carrier;

[0018]FIG. 3 is a bottom view of the same fiber-carrier;

[0019]FIG. 4 shows one end of the same fiber-carrier;

[0020]FIG. 5 is a sectional view of a lateral wall of the same fiber-carrier;

[0021]FIG. 6 is a sectional view of a cap in accordance with the invention adapted to receive the fiber-carrier from FIGS. 1 to 5;

[0022]FIG. 7 is a view in longitudinal section of a handle for a brush in accordance with the invention adapted to be assembled to the cap shown in the preceding figure;

[0023]FIG. 8 is a view in longitudinal section of a brush in accordance with the invention obtained by assembling the components from FIGS. 1 to 7;

[0024]FIG. 9 is a view in longitudinal section of a different embodiment of a brush according to the invention;

[0025]FIG. 10 is a view in longitudinal section of a different embodiment of a brush according to the invention; and

[0026]FIGS. 11 and 12 are respectively side and front views of the handle for a further embodiment of the brush.

[0027] The brush that will be described is a flat brush but could equally well be rectangular, round, oval or any other shape. It comprises four main components, namely a fiber-carrier 100, a tuft of bristles 200, a cap or ferrule 300 and a handle 400.

[0028] The fiber-carrier 100 takes the form of a plastics material, here polyacetal, container having a bottom wall 105 and a circumferential wall 110 forming a rim around the bottom wall.

[0029] The bottom wall 105 has an elongate shape with two rectilinear sides and two semicircular ends.

[0030] The fiber-carrier 100 is adapted to receive firstly a layer of glue 112 in the bottom and then the tuft of bristles 200.

[0031] To this end the bottom wall 105 is a solid wall forming in conjunction with a base portion of the lateral wall a cup adapted to receive the glue before the fibers are inserted.

[0032] However, the lateral wall 110 includes a series of orifices 115 slightly offset relative to the bottom of the fiber-carrier and in this example each orifice is circular and has a small diameter (approximately one quarter the height of the fiber-carrier).

[0033] The glue is introduced into the fiber-carrier and enters the orifices 115. The glue not only espouses the internal contours of the orifices 115 but also passes through the orifices into anchor cavities adjacent the orifices.

[0034] When the tuft of fibers 200 is introduced into the glue 112, the glue rises a small distance along the fibers and between the fibers and the lateral wall 110.

[0035] The orifices therefore have a first function of forming an anchor cavity for the glue when hardened and a second function of providing a fluidic passage toward anchor arrangements forming part of the remainder of the brush. The latter anchor arrangements are described hereinafter. They anchor the glue and therefore also the fibers.

[0036] The orifices 115 are distributed over the periphery of the fiber-carrier across the width of the brush.

[0037] The regular distribution of the orifices 115 in the rim of the bottom wall 105 and at a constant height relative to the bottom wall means that the same amount of glue exits over substantially all the length of the fiber carrier after inserting the bristles. The final height of glue inside the fiber-carrier is therefore homogeneous.

[0038] A final thickness of glue from 1 to 5 mm proves to be satisfactory from the point of view of the strength and flexibility of the tuft, with the thickness more advantageously from 2 to 4 mm and ideally equal to 3 mm.

[0039] Of course, a homogeneous distribution of the orifices is also easy to provide in the case of round brushes, and any of the features proposed hereinabove and hereinafter can also be adapted to a round brush.

[0040] The circumferential wall 110 comprises two ribs 120 parallel to the bottom wall and extending over the whole of the contour of the fiber-carrier, between the series of orifices 115 and a top free edge of the wall 110.

[0041] Alternatively, the ribs can extend over only a portion of the contour.

[0042] The ribs 120 are accommodated in corresponding grooves 320 in the inside wall of the cap 300 to locate the fiber-carrier 100 in the cap or ferrule 300 and hold it in place before pouring the glue and inserting the bristles.

[0043] The outside face of the circumferential wall 110 is perpendicular to the bottom wall 105.

[0044] However, the wall 110 has on its inside face a globally oblique surface which diverges from the center of the fiber carrier in the direction away from the bottom wall 105. This diverging orientation is advantageously adopted over the whole of the inside perimeter of the receptacle, as here, but can be adopted over only a portion of the inside perimeter.

[0045] In other words, the inside face of the wall 110 is globally funnel-shaped, obtained in this example by reducing the thickness of the wall 110.

[0046] To be more precise, an inside surface of the wall 110 has an oblique part 117 halfway up the height of the wall 110 and between top and bottom portions 116 and 118 which in this example are both at right angles to the bottom wall 105.

[0047] To be more precise, the half-height portion 116 adjacent the bottom wall 105 has an inside face at right angles to the bottom wall 105 and the last third-height portion 118 adjoining the free edge is also at right angles to the bottom wall 105. Between these two portions, the oblique portion is at approximately 80° to the bottom wall 105 of the fiber-carrier.

[0048] This generally flared inside shape of the fiber-carrier constitutes a funnel for introducing the tuft of bristles and allows the fibers to flex freely by a chosen amount inside the fiber carrier 100.

[0049] The fact that the inside face comprises two portions, the portion 116 at the bottom end being less steeply inclined than the portion 117 farther away from the bottom, is particularly advantageous.

[0050] The bottom portion 116 of the wall, because of its right-angled orientation, holds the outermost fibers vertical while the glue is hardening. The more oblique portion 117 allows inclination of the fibers, primarily when they are subjected to a lateral force.

[0051] Because the fibers are allowed to flex inside the fiber-carrier 100, the overall flexibility of the tuft 200 is increased, in particular at the base of the tuft, giving an improved quality of application (better application and better spreading).

[0052] What is more, because the inside of the lateral wall 110 first extends vertically and then obliquely, the lateral wall 110 is slightly spaced from the tuft of bristles 200 above the oblique part 117.

[0053] This kind of interstice between the tuft 200 and the side 110 retains any paint or solvent flowing into the interior of the fiber-carrier 100, so preventing it from dripping over the outside of the brush onto the handle, as occurs with conventional brushes.

[0054] The interstice has a height adapted to retain a satisfactory quantity of paint, in particular in the oblique portion 117 and the right-angle portion 118 adjoining the free edge.

[0055] Because the orifices 115 are blocked by the glue the fiber-carrier 100 forms a sealed container to prevent dripping up the bristles and onto the handle along a path inside the brush, as occurs with conventional ferrules. To achieve this the orifices 115 are made sufficiently small, in conjunction with a sufficient quantity of glue.

[0056] The polyacetal used here for the fiber carrier has mechanical and chemical properties which are identical to those of a metal but without the risk of oxidation.

[0057] Because the fibers are spaced from each other and because the fiber-carrier 100 is globally flared, the fibers flex inside the fiber-carrier, imparting great flexibility to the tufts 200, i.e. good quality of application and good ease of use.

[0058] There is in particular a main flexing area, which in this example is inside the fiber-carrier 100, whereas in conventional brushes with ferrules the main flexing area is approximately one third of the way up the height of the fibers.

[0059] However, particularly heavy forces are applied to the layer of glue, which in particular is pulled towards the front of the brush along its longitudinal edges. It has therefore proved advantageous to distribute the orifices along the longitudinal edges to enable the use of a particularly thin layer of glue.

[0060] To enhance the effect of retaining any drips of paint or solvent, the lateral wall 110 has a circumferential rib 125 on its outside face level with its free edge.

[0061] The rib 125 has a plane face 127 perpendicular to the main axis of the brush facing toward the end of the tuft 200.

[0062] The face 127 forms a barrier against any drips running along the tuft and retains them on the tuft, deflecting them towards the inside of the fiber-carrier.

[0063] The cap 300 shown in FIG. 6 is designed to fit over the fiber-carrier 100 with its free edge adjoining that of the fiber-carrier 100, extending the transverse barrier 127 farther toward the sides of the brush.

[0064] The plastics material cap 300 constitutes a generally flat envelope whose inside section is complementary to the outside section of the fiber-carrier 100 and extends over a sufficient distance in the heightwise direction of the fiber-carrier 100 to receive both the fiber-carrier and a portion of the handle 400.

[0065] The cap 300 includes a pair of inside grooves 320 receiving the two ribs 120 on the fiber-carrier to locate the fiber-carrier 100 accurately inside it, as already mentioned. The fiber-carrier also has stiffener walls, not shown, on the outside face of its bottom wail 105 which bear against the bottom wall of the cap 300.

[0066] The cap 300 has a rectilinear groove 330 on its inside wall which runs alongside each series of orifices 115 to receive the glue 112 passing through the orifices 115 and thereby to form an anchor cavity for the glue when hardened.

[0067] Thus in this example a brush of the above kind is manufactured by introducing bristles into a closed fiber-carrier fastened to the cap (and to the handle), the assembly therefore forming, prior to inserting the fibers, a quasi-inseparable handle/cap/fiber-carrier assembly, the fiber-carrier forming a receptacle with a bottom wall and lateral walls into which a metered quantity of liquid glue is dispensed before inserting the fibers.

[0068] The nature, length and density of the fibers are adapted to suit the product to be applied. In the present instance of a paint brush, the density of fibers at the level of the layer of glue is less than 0.55 g/cm³.

[0069] The density is substantially the same in the free part of the tuft, and as far as its free end, so that the tuft has an aptitude for flexing which is substantially homogeneous over all of its height, from its end fixed into the glue, inside the receptacle 100, to its free end.

[0070] This produces a homogeneous spacing between the fibers which gives the tuft a satisfactory paint retention capacity combined with the facility for relative movement of the fibers inside the receptacle.

[0071] The regularity of application (quality of spreading) is therefore significantly improved by choosing homogeneous fiber densities. No mass of paint is formed under the brush during application.

[0072] The density, which is not controlled in the prior art, is made homogeneous and is adapted to suit the product to be applied, which imparts a greater flexibility to the tuft for the same length of bristles (equal draw). The increased flexibility improves both spreading (smooth and regular appearance of the layer of paint) and application (the quantity of paint taken up each time the brush is dipped into the paint).

[0073] What is more, gluing the bristles directly to the member that retains them in the finished brush means that the density can easily be adapted because the fibers are naturally distributed across the whole of the layer of glue 112 which is their final extent in the finished brush.

[0074] In other words, because the fibers are glued directly together inside their final receptacle, the density of their distribution is naturally homogeneous and they accurately match the contour of the receptacle.

[0075] Placing the fibers with a chosen density is therefore easy, making use of the contours of the structure of the finished brush.

[0076] In a variant shown in FIG. 10 the receptacle for gluing the fibers is made up of two separate members, in that the bottom wall of the receptacle is an end face of the handle 400 and the lateral walls of the receptacle are the walls of a metal ferrule 500 which takes the form of a sleeve around the handle.

[0077] A layer of glue 412 is placed in the bottom of the receptacle, that is to say on the front face of the handle 400, and the tuft of fibers 200 is then plunged into the layer of glue 412, which hardens in contact both with the fibers and with the bottom of the receptacle, the fibers having a homogeneous distribution along the layer of glue 412 and espousing the sides of the receptacle.

[0078] The sides of the receptacle incorporate stamped portions of the ferrule in which the glue is accommodated and into which it becomes anchored when it sets.

[0079] The glue is also anchored directly to the handle 400, which in this example includes studs 410 engaged in the layer of glue 412 to retain it.

[0080] In a variant, the bottom of a fiber-carrier like the fiber-carrier 200 described with reference to FIGS. 1 to 8 is also provided with studs, pips or blades to retain the glue or the resin, in particular in the case of wide or thick brushes. These members are made in one piece with the fiber-carrier 200, for example, as shown in FIG. 9.

[0081] For fixing the handle 400 in the first variant, shown in FIGS. 1 to 8, the cap 300 forms at the end opposite the tuft 200 a cover through which passes an orifice for receiving the handle 400.

[0082] To this end the cap 300 forms a re-entrant tubular passage 340 forming a receptacle for a corresponding end tube 440 of the handle 400, the tube 340 incorporating an annular groove 345 at its inside end and the tube 440 being provided with an annular rib corresponding to the groove 345. The groove 345 is preceded by a retaining rib 347 which is on its upstream side with respect to the direction of insertion of the handle 400.

[0083] In the main plane of the cap 300, the contour of the cap has a rounded shape around the fiber-carrier 200 and forms at its center a U-shaped cavity 350 which is open toward the fiber-carrier and the bottom of which is extended by the retaining tube 340.

[0084] The thickness of a substantially flat handle 400 is similar to that of the ferrule 300 and its end portion adjacent the cap 300 has a U-shaped contour which is complementary to that of the U-shaped cavity 350 of the cap 300 and which also forms, at the base of the U-shape, the tube 440 which is inserted in the passage 340.

[0085] The U-shaped contour end portion of the handle therefore locates in a cavity the same shape as the cap 300.

[0086] The U-shaped cavity 350 of the cap 300 has lugs 355 on the inside face of the sides of the U-shape which engage in complementary cavities 455 on the outside faces of the U-shaped contour of the handle 400. These lugs and cavities prevent the handle 400 from rotating relative to the cap 300.

[0087] These features enable a handle 400 with the same dimensions to be used for different widths of brush head.

[0088] The handle 400 has a thinner portion near where it is joined to the cap 300, which provides a good grip and facilitates applying a final coat.

[0089] A projecting wall, not shown, on the outside face of the bottom wall 105 of the fiber-carrier 100 extends into the handle 400 through its open end, i.e. the inside of the tube 440.

[0090] That wall is perpendicular to the main plane of the brush and its width is equal to the inside diameter of the tube 440. The wall therefore forms an arm preventing tilting of the fiber-carrier 100 inside the cap 300, in particular tilting about an axis in the plane of said brush and perpendicular to its main axis.

[0091] To prevent tilting in all directions another wall can be provided in another direction or the aforementioned walls can be replaced by a complete cylinder.

[0092] The cap 300 therefore forms a wide envelope whose volume extends around the fiber-carrier 200 and beyond it, toward the handle 400, as well as over the sides of the handle.

[0093] The volume of the cap 300 adjoining the handle 400 is practically empty. The brush is therefore particularly light in weight. What is more, a longitudinal cavity 450 further reducing the weight of the brush extends through the handle 400 and is surrounded by the handle over its entire length.

[0094] Because of this sealed inside volume, when the tuft is immersed in a liquid, for example paint or solvent, the brush is lighter than the liquid and therefore floats. Thus if the brush is left in a can of paint or a jar of solvent, for example, it is immersed in the liquid to only a moderate depth, with the handle above the surface of the liquid.

[0095] In this example the interior volumes of the handle 400 and the cap 300 communicate with each other and means are provided for sealing their combined volume.

[0096] The internal cavity 450 of the handle 400 is open only at the front end of the fixing tube 440, communicating with the interior volume of the cap 300, and the two fixing tubes 340 and 440 are respectively provided with a rib 345 and an annular groove 445 sealing the passage between the two empty spaces.

[0097] The interior cavity 450 of the handle can receive a filament or other member adapted to activate a shoplifting detector as routinely used in supermarkets, for example.

[0098] The connection of the cap to the fiber-carrier 200 is also sealed by the cooperation of the circumferential ribs 120 on the fiber-carrier 100 with the corresponding internal grooves of the cap 300.

[0099] This sealed connection prevents paint flowing into the interior of the cap 300 and the handle 400.

[0100] However, even if paint were to flow into the cap 300, it would not come into contact with the user's hand because the cap 300 assembled to the handle 400 forms a sealed envelope or barrier between the fibers and the user's hand.

[0101] Solvent can rise up the tuft 200 through the means for retaining the tuft 200, but only as far as the outside surface of the handle 400. In conventional brushes and ferrules solvents can pass through the ferrule as far as the handle

[0102] The fact that the fiber-carrier 100, which is joined to the cap 300 by its contour, also forms a sealed barrier at the connection facilitates cleaning because no solvent can be retained above the tuft 200. This can occur with ordinary brush heads, in which solvent can inconveniently flow out from the ferrule when the user resumes painting. The tuft 200 can therefore be cleaned in complete safety right down to its base, preventing paint from accumulating there.

[0103] The means providing this protection by means of a seal at the cap/fiber-carrier junction are invisible to the user.

[0104] Beyond the end of its inside cavity 450 opposite the tuft of bristles 200, the handle 400 has an opening 460 forming a transverse passage for hanging up the brush which has an elongate cross section in the plane of the handle extending over substantially half the length of the handle 400. This transverse passage is also adapted to receive a colored insert or an insert carrying the brand of a distributor of the product.

[0105] In accordance with advantageous but non-limiting features:

[0106] the cap 300 (or ferrule) shown in FIG. 6 is separate from the fiber-carrier (or receptacle) 100;

[0107] alternatively, the cap 300 and the fiber-carrier 100 are formed by one and the same member;

[0108] the layer of glue 112 therefore hardens once only in simultaneous contact with the fibers and with the bottom wall of the fiber-carrier (or receptacle) 100;

[0109] the inside surface of the wall 110 has, toward its free end and beyond the second portion 117, a third portion 118 that is inclined in the outward direction less than the second portion 117;

[0110] the ferrule surrounds the end of the receptacle 100 opposite the tuft of fibers 200 and borders the outside of the free edge of the lateral walls 110 of the receptacle 100 and the means 300 that surround a portion of the receptacle 100 at the end opposite the tuft of fibers 200 form a sealed envelope around that portion of the receptacle 100; and

[0111] the face of the handle 400 constituting the bottom of the receptacle is provided with means 410 embedded in the layer of glue 412 to retain it. 

1. A brush including: a handle (400), a ferrule (300)/receptacle (100) assembly joined to the handle (400), a layer of glue (112) inside the ferrule/receptacle assembly, and a homogeneous tuft of fibers (200) which has no built-in spacer, whose first end inside the ferrule (300)/receptacle (100) assembly is embedded in the layer of glue (112) and whose free second end emerges from the ferrule (300)/receptacle (100) assembly, in which brush the tuft of fibers (200) has an at least substantially homogeneous density throughout its length from its end embedded in the layer of glue (112) to its free second end, adapted to enable movement of the fibers in the ferrule (300)/receptacle (100) assembly so that, in use, the portion of the tuft of fibers (200) inside the ferrule (300)/receptacle (100) assembly and beyond the layer of glue (112) can flex, which brush is characterized in that the receptacle (100, 400, 500) includes arrangements on its lateral walls (110, 500) which form an anchorage for the glue and said anchorage arrangements (115) take the form of orifices (115) passing through the lateral walls (110) of the receptacle (100).
 2. A brush according to claim 1 , characterized in that the size of the orifices (115) is chosen in relation to the quantity of glue (112, 412) introduced into the receptacle (100) so that the glue blocks the orifices (115) after the bristles (200) are inserted.
 3. A brush according to claim 1 or claim 2 , characterized in that it includes a member (300) adapted to extend over at least two sides of the receptacle (100) and which has interior arrangements (330) forming an anchorage for the glue and said arrangements (330) face the orifices (115) of the receptacle (100).
 4. A brush according to any preceding claim, characterized in that the receptacle (100) and the ferrule (300) are two separate members.
 5. A brush according to any of claims 1 to 3 , characterized in that the receptacle (100) and the ferrule (300) are formed by one and the same member.
 6. A brush according to any preceding claim, characterized in that the layer of glue (112, 412) is hardened once only in simultaneous contact with the fibers (200) and the bottom (105, 400) of the receptacle (100, 400, 500).
 7. A brush according to any preceding claim, characterized in that the inside lateral faces (110) of the receptacle (100) are configured to diverge from the center of the receptacle (100) in the direction away from the bottom of the receptacle (100).
 8. A brush according to any preceding claim, characterized in that the lateral walls (110) of the receptacle (100) have a free edge slightly spaced from the edge of the tuft of fibers.
 9. A brush according to any preceding claim in conjunction with claim 7 , characterized in that the inside lateral faces (110) of the receptacle (100) have at least one portion which includes, in the direction from the bottom of the receptacle (100) to a free edge of its lateral wall: a first portion (116) at a given angle to the bottom, and a second portion (117) inclined more steeply than the first portion toward the outside of the receptacle (100).
 10. A brush according to the preceding claim, characterized in that the portion (110) extending from the bottom of the receptacle (100) to its free edge also includes a third portion (118) beyond the second portion (117) and at the same end as the free edge that is inclined less steeply toward the outside than the second (117).
 11. A brush according to any preceding claim, characterized in that the receptacle (100) has a free edge and a rib (125) along that free edge projecting toward the outside of the receptacle (100).
 12. A brush according to any preceding claim, characterized in that the ferrule (300) forms an envelope around the receptacle (100) on the side thereof opposite the tuft (200) and borders the outside of the free edge of the lateral walls (110) of the receptacle (100).
 13. A brush according to any preceding claim, characterized in that it includes means (300) surrounding the receptacle (100) around an end portion of the receptacle (100) opposite the tuft of fibers (200) and said means form a sealed envelope (300) around this portion of the receptacle (100).
 14. A brush according to claim 13 , characterized in that the envelope (300) is adapted to retain sufficient air in the brush for it to float in a liquid with the tuft of fibers (200) immersed therein.
 15. A brush according to any preceding claim, characterized in that the handle (400) includes a longitudinal passage (450) whose transverse contour is closed by the handle (400).
 16. A brush according to any preceding claim, characterized in that the layer of glue (112, 412) is from 1 to 5 mm thick.
 17. A brush according to any preceding claim, characterized in that the layer of glue (112, 412) is from 2 to 4 mm thick.
 18. A brush according to any preceding claim, characterized in that the layer of glue (112, 412) is approximately 3 mm thick.
 19. A brush according to any preceding claim, characterized in that the density of the fibers at the level of the layer of glue (112, 412) is less than 0.55 g/cm³.
 20. A brush according to any preceding claim, characterized in that the bottom wall (400, 500) of the receptacle (400, 500) is formed by a face of the handle (400) and the lateral walls (500) of the receptacle (400, 500) are formed by the walls of a member (500) surrounding the handle (400).
 21. A brush according to the preceding claim, characterized in that the face of the handle (400) constituting the bottom of the receptacle (400, 500) is provided with means (410) projecting in the layer of glue (112, 412) to retain it.
 22. A brush according to any of claims 1 to 3 or any of claims 5 to 21 when not combined with claim 4 , characterized in that the handle, the receptacle and the ferrule are formed by one and the same member. 